Alternating-current magnetic apparatus.



No. 837,853. PATENTED DEC; 4, 1906.

I D. LARSON.

ALTERNATING CURRENT MAGNETIC APPARATUS.

APPLICATION FILED NOV. 15. 1905.

lNl/ENTOR ATTORNEY UNITED STATES PATENT OFFICE.-

1)Avm LAasoN, 0F YoNKERs, NEW YORK. 'ALTERNATlNG-bURRENT MAGNETIC APPARATUS.

Specification of Letters Patent.

Patented Dec. 4,

Application filed November 15, 1905. Serial No. 287,478.

To all whom {It may concern:

Be it known that I, DAVID LARSON, a subject of the King of Sweden, and a resident of Yonkers, New York, have invented certain new and useful Improvements in Alternating- Current Magnetic Apparatus, of which the following is a specification.

My invention relates to alternating-current magnetic apparatus for use in conjunction with alternating intermittent or pulsating current; and its object is to provide sim 1e and eflicient apparatus of this kind which will be free from the chattering noise which is usually found in alternating-current apparatus. I g

I will describe my invention in the followingspecification and point out the novel features thereof in claims.

Referring to the drawings, Figure 1 is a diagrammmatic representation in side elevation of an electromagnetic apparatus made according to my invention an applied to an electrically-actuated brake. Fig.2 shows a modification of my invention, ap lied in this case to actuate a motor-starting r ieostat; and Fig. 3 is another modification of my invention, in this case applied to actuate a valve.

Like characters of reference designate corresponding parts in all of the figures.

designates an electromagnet, which comprises a frame 11, preferably constructed of laminated magnetic material, a winding or coil 12, arranged to energize this frame, and

an armature 13, also constructed of laminated magnetic materiaL. This armature may be pivoted, as shown in .Fig. 1, at 14. g

designates the 'mains from a suitable source of an electrical supply, which, after passing through a transformer 21, may-be connected, bymeans of a manually-operated switch 22, to the coil or winding 12 of magnet 10.

Referring now to Fig. 1,30 designates a brake-pulley rigidly mounted upon a. shaft 31. Brake-shoes 32 32 are arranged to be supported upon levers 33 33, which are pivoted at 33 33 and are arrangedto bepressed against the pulley by means of springs 34 34. These springs are arranged to press upon the outside of levers 33 33, and them tenslonma be regulated by means of nuts 35 35, which are on the'outside ends of a rod 36, which exhave.

tends through both of the levers 3 33. The levers 33 33 are connected together by means of two other levers 37 37, which are connected to levers 33 33 by pivots 37 A 37 and are connected, together at their other ends by pivot 37 and are in the position shown by full lines in the drawings when the brake-shoes 32 32 are applied to t e brake-pulley. The pivoted connection 37 is connected to the armature 13 at the point 15 by a rod 38. The

strength of the magnetic knee in the magnetframe 11 will be used first to move the toggle connections and release brake-shoes 32 32; but after these mechanical arts have been moved the opposing efiect oi the mechanical arts upon armature 13 will, nearly all of it lie removed. Consequently nearly thetota strength of magnet 10 will be expended upon keeping the armature 13 against the polepieces 11 and 11. This will cause the parts to be firmly held together, and will obviate the chattering noise which such parts usually Before describing the other figures I will point out the operation of the apparatus above described.

When the various .parts are at rest, they are in the relative ositions in which they are shown by the full lines of Fig. 1, except that in this case the switch 22 will be open. Now if the switch 22 is closed and the magnetwinding 12 is thereby connected to the source of supplya current will fiow'through this winding andwill energize magnet-frame 11. This will cause the pivoted armature 13 to be drawn up a -ainst the oles 11 and 11 of the magnet rame. T e movement of pivoted armature 13 will be opposed by the springs 34 34 through ,the mechanical connections above described and will thus make a load upon armature 13. This load will be of maximum strength at, the be ning of this operation and will be gradual y reduced as the armature 13 moves. When armature 13 has completed its movement, so that it is abutting 'against the pole-pieces 11 and 11, and thereby closes the magnetic lines which are setup in magnetic frame 11 and closes the magnetic circuit, the connectinglevers 37 37'w1ll be nearly in alinement with too each other. In other words, the-connections of the levers are so arranged that they cor stitute a toggle-joint. 'Itmaybc seen, therefore, that as armature 1.3 is moved the load which it"controls will be gradually shifted from the armature onto the supports oi. the various levers. The movement of armature 13 through the mechanical connections will release brake-shoes 32 32 from the brake-pulley 30. I

It is desirable to arrange the partsso that the connecting-levers 37 37 will not be quite in alinement with each other after the magnet-armature- 13 has been moved, sotha-t when switch 221is o ened: and the magnet is d'e'energizedthe torce of the springs 34 34 will cause theparts to move back again into their original positions and app] bra-keshoes- 32 32to the brake-pulley Wli1ll11ltLXimum strength.

Fig; 2 shows a modification of: this invention. In this case n'iagnctfranie 1-1 is arranged to= inclose asolenoid-winding 12, which when energized will attract and' raise a core- 13. An antifriction-roller 40 may be provided at the end of this core 13 and arranged to work in theslot 41' of a cam-lever 42', which ispivoted at 43. A connectingrod-44 isconnect-ed'to the cam-lever 42 at 45 and tea vertically-sliding rod at 46. This rod 50 is supported by a stationary bracket 5-1 and carries at its lower end a sliding contact-piece 52', which is connected to but insulated from the sliding rod 50. The parts above describedmay normally remain in the positions shown under the force of gravity, or a spring 53'1nay be added for the urpose of returning the parts to their initizTpositions after they have been operated. The sliding contact-piece 52 is arranged to be moved up over a stationary contact-piece 54 and a plurality of stationary contacts 55, to which a resistance 536-111 a y be connected. In this view, Fig. 2, and 61 designate two mains from a secondary source of supply, which may be connected, by means of a manually-opcrated switch 62, to the armature 63 and series field i 64 of an electric motor through conductor 65, resistance 56, and conductor 66. Thus acircuit will be completed whencrcr switch 62 is closed from the mains 60 and (:1 through the motor and resistance. Now if switch 22 isclosed, so that solenoid-winding 12 is energized thereby, the core 1. 3 will be raised, and its roller 40, acting upon the inside oi slot 4] will raise the sliding rod 50 and movable contact 52, so that the latter will cut out resistance 56 in a series of steps. It may be seen that after solenoid 13 and its connected parts have been raised the inside of slot 41 of the cam member 42 will be in a nearly vertical position, so that nearly all of. the strength of the magnetic lines in frame 11" may be expended in holding core 13' against a projecting core 16, which is a part of magsenses l net-frame 11. In this way the core 13 will be held lirmly against the irojecting core 16 and be prevented thereby rom chattering.

In Fig. 3 the electrical connectionsand magnet 10 are shown similar to those already described in Fig. 1. The armature 13 is pivoted at 14", as before described; but in this case the arm which supports the armature is provided. with gear-teeth 70. These mesh with the teeth of a pinion 71, which is pivoted at 72. Attached to pivot 72 is an arm 73, to which is connected at 74 a rod 75. This rod is connected at 76 to a lever 80. This lever is pivoted at 81 and is weighted by a sliding weight 82. The valve 90 has its piston 91' connected by a rod92 to this pivoted arm 80. The weight 82 may keep the valve 90 in closed position, and the magnet 10, through the connecting mechanism which is described, may raise the valve, and thereby open it. It may be seen that in this case as the magnet 10 attracts itsv armature 13", and thereby raises pivoted arm 80, the load upon the armature will be the arm 80, and it is connected to valve 90, and that as pivoted arm 73 is moved about pivot 72 until it proximates ail-upright position the load upon magnet 10-will be reduced to a minimum, so that the strength of the magnet may be utilizedto firmly hold the armature 13 against its polepieces 11 andll.

I have shown that this invention is applicable to several forms oi apparatus; but it is by no means limited to those herein described.

and described for reducing the load upon an alternatingmurrent magnet from a maximum to a minimum during the movement of the magnets armature or core, so that after the load which it is adapted to move has been moved, nearly the entire strength of the magnet may be utilized for holding the parts firmly together and for thus preventing chattering noises. is broadly new.

It is a wcll-known 'l'act that the chattering noise accompanies alternating-current magnets, especially when such magnets are encrgizcd by asingle-phase current, and es ecially whcnthey are arranged to lift a loa( This is obviously due to the alternationsof the current and the intermittent variations of magnetic strength.

In the present invention the magnets armature is placed within reach of the magnetic attraction of the magnet, so that when the magnet is energized it will attract its armature and allow the latter to accomplish the work for which it is intended. The mechanical connections are such as to give the armature a com aratively small movement and to allow the oad' upon the armature to be diminished from a maximum to a minimum, so that the armature may be held tightly against It is believed that the means herein shown the magnet to close the magnet-lines and to be held firmly against the magnet. They are also such that upon returning to their original position the efl'ective load Wlll again be 1ncreased to its maximum.

What I claim is g 1. An alternating-current magnet, an ar mature arranged to be moved thereby, a load connected to and carried by the armature, and means for reducing said load so that it is not all carried by the armature after the armature has been moved by the magnet.

2. An alternating-current magnet, an armature arranged to bemoved thereby, a load connected to and carried b the armature and means for reducing said oad from a maximum to a minimum as the armature is moved by the magnet.

3. An alternating-current magnet, an ar mature arranged to bemoved thereby a load for the armature, intermediate mec ianism connecting the load to the armature and arranged to diminish the effect of the load upon the armature as the armature is moved by the magnet.

4. An alternatin ecurrent magnet, an armature arranged to e m'oved thereby, a load for the-armature, intermediate mechanism connecting the load to the armature, said mechanism being arranged to gradually take the load from the armature as the armature is moved.

5. An alternatin -current magnet, an armature arranged to be moved thereby, a load for-the armature, levers connecting the load to the armature and arranged to diminish the effect of the load upon the armature as the arn'lature is moved by the magnet.

6. An alternatin -current magnet, an armature arranged to )e moved thereby, a load for the armature, levers connecting the load to the armature su nuts for the levers said J 7 levers being arranged to diminish the effect of the load upon the armature as the armature is moved by the magnet.

-7. An alternating-current magnet, an armature arranged to be moved thereby, a load for the armature, levers connectin the load to the armature, supports for the levers and for the. armature, said supports being arrarwcd to hold the load after the armature has hcen moved by the magnet.

8. An alternating-currentmagnet, an armature arranged to be moved thereby, a load for the armature, levers connecting the load to the armature, supports for the-levers and for the armature, said supports being arranged to hold the load after the armature has been moved by the magnet, said levers arrangcdto diminish the effect of the load on the annature as the armature is moved by the magnet.

9. An alternating-current magnet, an armature arranged to be moved thereby, a load for the armature, levers connecting the load to the armature, supports for said overs and armature, the movement of the armature and the mechanical connection of the lovers being arranged to shift the load from the armature onto said supports.

10. An alternating-current magnet, an armature arranged to be moved thereby, a load for the armature, levers connectin the load to the armature, supports for said levers and armature, the movement of the armature and the mechanical connection of the levers being arranged to shift the load from the armature onto said supports as the armature is moved. 11. An alternating-current magnet, an armatureand a load arranged to be moved armature arranged to be moved thereby said armature a so constructed of laminated material, a load for the armature, intermediate mechanism connecting the load to the armature and arranged to diminish the effect of the load upon the armature as the armature'is moved by the magnet.

13. An alternating current magnet, a winding therefor, a source of single-phase alternating-current supply, means for connecting said winding to the source of supply, an armature arranged to be moved by the magnet, and means for mechanically 0 posing the pull of the magnet, said means ein arranged to have less opposition effect to the pull of the magnet after the armature has been moved by the magnet.

14. An alternating-current ma met, a winding therefor, a source of' sing e-phase alternating-current supply, means for connecting said winding to the source of supply,

an armature arranged to be moved by the magnet, a load for the armature intermediate mechanism connecting the load to the armature and arranged to diminish the ef-- feet of the load upon the armature as the armature is moved by the magnet.

15. An alternating-current magnet constructed of laminated magnetic material, a winding therefor, a source of single-phase alternating-current supply, means for eonnecting said winding to the source of supply, an armature constructed of laminated magnetic material, intermediate mechanism connectin the load to the armature and arranged to diminish the effect of the load upon the armature as the armature is moved by the magnet.

the armature has been released by the magesmsee 16; An alternating eurrent magnet, anatmature arranged-to be movedthereby, a load connectedlto and carried by the armature, and means-for reducing said load so that it is not all carried by the armature after the armature has been moved by the magnet, and for increasing the load to a maximum after part, means for mechanically opposing the movement, said means being arranged to have less opposition effect after said part has 15 been moved.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

net. DAVID LARSON. I

. 17. An alternating-current'magnet, comprising two parts, one of which 18 movable and is arranged to be moved by the other Witnesses:

ALFRED C. BECHET, W. H. GanmsoN. 

